On the 2.2 subject, see you brought this one up , I did have 2.2 Manual LPG to drive around in for a little while, and was quiet surprised how bad it was on MPG compared to the LPG'd V6's Ive driven.
Consistent 27mpg I would get, never really had lower than 22 over an entire tank. Record was 31 on long run, all LPG figures.
With 3.2 getting 23/24mpg on petrol, I would expect around 17/18mpg on gas.
Yea, the 22mpg on Gas was with a lot of stop starts, probably more stopping then starting if Im honest in Central London.
17/18 mpg 3.2 Auto on LPG, yea I would agree with that, what did i say above 18/19.
The way I would look at it, getting LPG sub 60p, would be even 15mpg is basically 30mpg in terms of cost. So why not have a heavy right foot!
Shell on M3 Sunbury though clearly don't want LPG on their forecourt any more, 65.9 when I drove past last week.
More, a lot more, lets take your 3.2 and your commute to work, I'll base the Cost on around here because I know the Prices, Petrol at 1.229 perL, LPg around here is 53/54p, lets call it 55p perL, if you doing 24 MPG with your right slippers on then you should easy be able to do 20/21 mpg on Gas but lets call it 19mpg .
So Maths based on current Petrol and LPG Prices.
Gallon of Petrol £1.229 L x 4.55 = £5.59 Gal, / by 24mpg =
23.3p per Mile.same cost on lpg
£5.59 worth of Gas / by 55p = 10.16 L, / by 4.55 = 2.23 Gals, x 19 =
42.4 MPG equivalent and
13.2p per Mile Plus, as you already know, where your really going to see the cost benefits of LPG is on a nice long Run where you can push your average MPG up even more